Pretty much what it says on the tin. I powered through Babylon in just three days due to the promise of 30 free Quartz, and now I only have five days left until Solomon opens up proper. With so many servants I have needing the same materials for upgrades, I can only pick one to upgrade. And so, who should I pick?
I have St. Martha ready for her job of cleansing, as she was one of my two starters servants along with Lancer Elly from the tutorial roll. However, due to her lack of damage or any use outside of her niche, I left her at L50 this whole time. I need to farm the full complement of 15 Dragon Fangs for second ascension, but I have the materials for the rest of her (although it pains me to give her Chaos Claws when Jack wants them more for skill levels, and I need to farm all the exp such a big level up requires).
Robin Hood is basically in the same boat, except instead of choosing not to level him, I just put him under Emiya in priority, and by the time I fully ascended the latter, I was out of Dragon Fangs for Robin's final form (downside is he's still only NP3 despite being a cheap 3*).
Lastly, my support quartet of Caesar, Andersen, Mozart, and Shakespeare have all been trapped at ascension level two despite being some of my original servants, due to the fact that they *all* need Pages and Gears to ascend, and I needed those materials for more primary servants (Gears are the worst thing ever). Each has immediate merit to pick to level, but who has more merit is up to debate, hence my looking for opinions.
Given these valuable assets in need of aid, and the fact that I can only choose to elevate one, who should I put my focus towards? (I don't plan to roll for Merlin or try to get Zhuge for New Years, as much as people will think me stupid for it, so farming for their materials to boost is out).
Edit: See below for a list of available combat-ready servants I already have.